Stainless Steel Microspheres

300 Series stainless steel is well known for its corrosion resistant properties. Now Scientists are demanding high quality spherical stainless steel microspheres which offer high density (7.8g/cc), high sphericity (>90% round) and corrosion resistance (300 series stainless steel).

A full range of precision sizes are now available from 1-22um on up to 1.0-1.2mm.

Research vial quantities are listed, many sizes have kg quantities in stock for larger project needs.

Deformable Silver Coated PMMA Microsphere Spacers

Silver Coated Glass Microspheres work well for increasing the conductivity of bond lines, but they lack the capability to deform when compressed to give increased conductive contact between the surfaces of the bond line. These newly released Silver Coated PMMA Microspheres offer the low weight deformable pmma cores, and 250nm thick silver coating for high conductivity.

Conductivity of this product has been measured at <0.5ohm per square with a 30% by volume preparation. Sizes available cover both the common 50 micron (45-53um) and 100 micron (90-106um) sizes and many others.

These spheres are perfect for producing anisotropic (only conductive in one direction) conductive bond lines.

Actual bond line thickness achieved will be a function of the assembly pressure and the size spheres selected.

In addition to being high conductive these silver coated PMMA is bio-compatible.

Reflective Billboard – Creative Outdoor Billboard for McDonald’s

What a creative alternative to power-hungry digital displays. This large outdoor billboard is totally environmentally friendly because compared to LCD and LED displays that run on electricity, this display takes no energy to run. This creative outdoor billboard is made with reflective tape, visible only when illuminated by headlights in the darkness, created by ad agency Cossette. To promote a local 24-hour McDonald’s in Canada, Cossette Vancouver designed this reflective billboard that’s only visible at night when cars pass by. By day, the billboard appears blank with no message, but at night, motorists driving along the highway reveal Mickey-D’s clever advertisement with their car headlights. Not only does this display save energy, it can be put anywhere, even in cities with strict requirements on flashing and lit displays.

Even though this particular display was made using reflective tape, many types of retroreflective media can be made by incorporating retroreflective microspheres in a variety of substances. Retroreflective Microspheres are made by applying a half-shell aluminum coating on solid barium titanate glass microspheres. The spheres hemispherically coated with a thin aluminum shell produce a bright retroreflective response directed back to the light source.

Cospheric offers unique capability to manufacture Janus microspheres and microparticles with partial coatings and dual functionality. Currently half-shell or hemispherical coatings can be applied to any sphere (glass, polymer, ceramic) in sizes 45micron in diameter and higher. Coatings can be customized for any color and coverage of between 20% to 60% of the sphere. Each coating is custom formulated for color, charge, magnetic, electric, and surface properties, and solvent resistance per customers’ needs.

Hemispherical coatings of less than 1 micron with tolerances as low as 0.25 micron have been routinely demonstrated. Color combinations are truly unlimited. White, black, silver, blue, green, red, yellow, brown, purple as well as transparent microspheres have been made. Sphericity of greater than 90% and custom particle size ranges are offered.

Optically anisotropic spheres and janus particles with magnetic half-shells have been originally developed for applications in electronic displays, such as e-paper, but are now widely used in numerous applications in diagnostics, medical research, microscopy and biotechnology, as well as electronics, due to their ability to orient themselves in response to electromagnetic field and show a visual response. This is achieved by making spheres both bipolar and bichromal, with dipole precisely aligned with two differently colored hemispheres. As the spheres align themselves, the viewer will observe the color of one hemisphere, while the other hemisphere will be hidden from view, providing an obvious strong visible indication of the presence of the field or other stimuli. In alternating electromagnetic field, these microspheres have been proven to spin at hundreds of times per second.

Calculating microspheres per gram

During scientific experiment design and analysis it is common to need to know the number of spheres per gram of dry material. We have put together the table below to help speed up the process.

If you have material of a density different from those listed in the table, divide the number of spheres per gram in the density ~1.0 g/cc column by the true particle density of your material to get an estimate of the number of spheres per gram.

Product Size

Polyethylene
Density ~1.0 (g/cc)

Soda Lime Glass
Density ~2.5 (g/cc)

Lower (um)

Upper (um)

Spheres per Gram

Spheres Per Gram

20

27

147,162,715

58,630,564

27

32

74,393,558

29,638,868

32

45

33,467,185

13,333,540

45

53

16,233,536

6,467,544

53

63

9,788,528

3,899,812

63

75

5,813,720

2,316,223

75

90

3,401,258

1,355,083

90

106

2,029,192

808,443

106

125

1,239,525

493,835

125

150

734,672

292,698

150

180

425,157

169,385

180

212

253,649

101,055

212

250

154,941

61,729

250

300

91,834

36,587

300

355

54,371

21,662

355

425

32,196

12,827

425

500

19,305

7,691

500

600

11,479

4,573

600

710

6,796

2,708

710

850

4,025

1,603

850

1000

2,413

961

1180

1400

890

354

1400

1700

513

204

1700

2000

302

120

2000

2360

184

73

2360

2800

111

44

2800

3350

66

26

Note: This table assumes the mean diameter is half way between the upper and lower size.